Respirator



June29, 1937. E. w. BULLARD 2,085,249

RESPIRATOR Filed Oct. 2, 1955 INVEN TOR. 14/ BULL PD I775 A TTORNEY Patented June 29, 1937 UNITED STATES PATENT QFFME RESPIRATOR California Application October 2,

14 Claims.

My invention relates to a respirator, and more particularly to apparatus for supplying or conditioning air for a gas mask.

It is among the objects of my invention topro- 5 vide apparatus in which a primary unit supplies fresh air from a remote source, and in which a secondary unit for purifying the local air automatically becomes operative in the event the primary supply of fresh air is cut off.

Another object of my invention is to provide an auxiliary unit for operation in conjunction with the secondary or canister unit and by which oxygen may be fed into the air supplied through the canister.

A further object of my invention is to provide an assembly of the apparatus by which it may conveniently be carried on the person of the wearer.

The invention possesses other objects and fea- 20 tures of advantage, some of which, with the foregoing, will be set forth in the following description of my invention. It is to be understood that I do not limit myself to this disclosure of species of my invention, as I may adopt variant embodi- 25 merits thereof within the scope of the claims.

Referring to the drawing:

The figure in the drawing is an elevational view showing the respirator of my invention, portions of the apparatus being shown in vertical 30 section to illustrate the construction more clearly.

In terms of broad inclusion, the respirator embodying my invention comprises a breathing chamber from which air is drawn into a mask. A primary unit is provided in the apparatus for 35 normally supplying fresh air under pressure to the chamber from a remote source. A normally inoperative secondary unit is also provided for purifying the local contaminated air and supplying the same to the chamber, and means are provided for rendering the secondary unit operative when the primary supply of air is cut oil.

An auxiliary unit operable alone or in conjunction with the secondary unit is also preferably provided for introducing oxygen into the cham- 45 her.

In greater detail, and with reference to the figure in the drawing, the respirator embodying my invention comprises a frame 2 on the upper end of which a breathing chamber 3 is mounted.

50 A flexible duct 4 is connected to the breathing chamber 3, through which air may be drawn into a suitable mask on the face of the wearer and any ordinary gas mask having the usual exhaling valve may be used. The apparatus is sup- 5 ported on the body of the wearer by a harness 1933, Serial No. 691,833

preferably comprising a waist encircling strap 6 and a pair of shoulder straps l.

The shoulder straps are permanently fastened at their lower ends to the waist band 6, and are detachably connected at their upper ends to the chamber 3 by suitable buckles 8. The lower end of the frame 2 is connected to the waist band 6 by depending straps 9. Suitable buckles II are also provided in the straps 6 and l for adjustment of the harness. By this arrangement of the harness the apparatus may be worn on either the front or the back of the wearer.

A primary unit is provided in the apparatus of my invention for normally supplying fresh air under pressure to the breathing chamber 3 from a remote source, such as an air compressor. In fire apparatus the compressor on the truck may conveniently be employed. Since the pressure from such a source is usually around 100 pounds per square inch, I provide a valve for reducing this pressure to a predetermined value suitable for breathing purposes, say 2 pounds per square inch (gage pressure). The reducing valve is preferably constructed as a part of the chamber 3 and the volume of air supplied through the valve is preferably such as to maintain the pressure in the chamber at the predetermined value at all times.

This valve may be of any suitable construction. For purposes of illustration I have shown one comprising a spring loaded diaphragm l2 having connected thereto an outwardly extending yoke-shaped arm terminating in a valve head l3 seated over a restricted orifice it. The yoke shape of the supporting arm which mounts the valve head l3 for movement with the diaphragm l2 permits this arm to clear the internal part of the chamber casting. The diaphragm I2 is responsive to pressures in the chamber 3, and the loading of the diaphragm spring I5 is such that when the pressure in the chamber drops below the 2 pounds pressure the diaphragm will move to open the valve and allow more air to enter the chamber.

The compressed air is fed to the orifice [4 through a passage i6 from a feeder duct 11. The passage I6 is divided into two sections connected through a spring pressed check valve E8. The duct 11. is flexible and its lower end is anchored in a lug l9 bolted to the waist strap 6 of the harness. At this point the duct ll connects with a hose 2i which communicates with the source of air pressure.

The hose 2! may be of any length, depending upon the distance which the operator has to travel from the source of pressure. An important point in the construction to be noted is the anchoring of the hose 2! to the waist band 8 of the harness. This permits the hose to be dragged around by the operator without requiring the use of his hands, and without subjecting the apparatus to undue stress.

A normally inoperative secondary unit is provided for purifying the local contaminated air and supplying the same to the breathing chamber 3 in the event the primary supply of air is out off. Occasionally an operator, such as a fireman, becomes trapped in a position where he must cut his air hose in order to escape. At other times the supply of fresh air may be cut off by an accidental burning or cutting of the hose.

The secondary unit preferably comprises a canister 22 mounted on the frame 2 and connected to the breathing chamber 3. A hinged clip 23 is preferably provided for demountably fastening the canister. This canister provides a passage communicating with the atmosphere and opening into the breathing chamber. The element or agent 24 in the canister by which the poisonous air is rendered harmless may be of any suitable composition.

The passage of air through the canister is controlled by a suitable spring pressed check valve 25, preferably seated on the apertured bottom of the canister so that the lower side of the valve is exposed to atmospheric pressure. This check valve is arranged so that it is closable by pressure within the breathing chamber, so that the valve stays closed as long as the pressure in the chamber is above atmospheric pressure, but opens as soon as the pressure in the chamber drops below atmospheric pressure. As long as the pressure conditions in the chamber 3 are merely affected by the inhaling of the operator the valve 25 will open and close in time with the breathing, but while the fresh air is being supplied to the chamber, and the pressure maintained above atmospheric pressure, the valve 25 will be held closed.

The valve 25 therefore automatically operates to throw the secondary or canister unit into operation when the primary supply of air fails. Of course when the air pressure is cut off the check valve l8 closes to seal the chamber against the entrance of gas through the duct H.

An auxiliary unit is also preferably provided for supplying oxygen to the breathing chamber in the event sufficient oxygen is not supplied through the canister. I This unit comprises a container or tank 26 for holding a supply of oxygen under pressure, preferably at about 2000 pounds per square inch. This tank is removably held on the frame 2 by a suitable clip 27, and is preferably positioned with its neck or valve end down. The tank is connected to the chamber by a suitable duct 28. Communication between the tank and chamber is controlled by a hand valve 29. The positioning of this valve adjacent the lower portion of the apparatus permits an operator to readily reach it when the apparatus is being carried on his back.

A reducing valve 39 is also provided in the line of communication beween the tank and chamber for reducing the pressure to some predetermined value suitable for breathing purposes, say 2 pounds per square inch. The passage for the oxygen leading into the chamber 3 however is comparatively small, so that only small quantities of the oxygen are fed into the chamber, In this respect the introduction of the oxygen differs from the introduction of the fresh air. The latter was introduced in quantities sufficient to maintain the pressure in the chamber above atmospheric pressure, thereby holding the canister valve 25 closed. In the case of the oxygen however the pressure in the chamber is not materially affected, and the valve 25 opens and closes with the breathing of the operator in the usual manner.

With a small duct or passage between the oxygen bottle and breathing chamber the reducing valve 3E] may be unnecessary as the hand valve 29 may be opened but slightly thereby allowing a small trickle of the gas to pass. It is also to be understood that the oxygen can be used alone in the breathing chamber for 7 or 8 minutes. With a proper control of the gas pressure in the breathing chamber the canister valve 25 can be made either operative or inoperative, so that the oxygen may be supplied either pure or in conjunction with air drawn through the canister.

For the convenience of an operator I also preferably provide an electric lamp 32 mounted on an arm 33 terminating in a ball and socket joint 34 at one end of the chamber 3. Current for the lamp is preferably provided by batteries held in a tubular casing 36 formed as an integral part of the frame 2.

I claim:

1. A respirator comprising a breathing chamber, a canister connected to the chamber, a duct for supplying fresh air under pressure to the chamber from a remote source, and a spring pressed check valve in said air duct openable under the air pressure for automatically sealing the duct when the pressure is cut off by severance of the duct at a point spaced from and independent of the valve and its mounting.

2. A respirator comprising a breathing chamber, a spring pressed check valve, 2, primary unit for normally supplying fresh air under pressure past said valve to the chamber from a remote source, said spring being loaded to hold the valve closed against atmospheric pressure but yieldable to open the valve under the pressure of the fresh air being supplied, a normally inoperative secondary unit for purifying the local contaminated air and supplying the same to the chamber, and means responsive to pressure within the chamber less than atmospheric pressure for rendering the secondary unit operative when the primary supply of air is out off.

3. A respirator comprising a breathing chamber, a duct connected with said chamber, means for supplying fresh air under pressure to said chamber from a remote source through said duct, and means associated with said duct and responsive to the pressure of the air being supplied for feeding the air to the chamber and for automatically sealing the duct when the pressure is cut off by severance of the duct at a point spaced from the sealing means.

4. A respirator comprising a breathing chamber, a duct connected with said chamber, means for supplying fresh air under pressure to said chamber from a remote source through said duct, and means associated with said duct and located adjacent the chamber and responsive to the pressure of the air being supplied for feeding the air to the chamber and for automatically sealing the duct when the pressure is cut off by severance of the duct at a point spaced from the sealing means.

5. A respirator comprising a breathing chamber, a duct connected with said chamber, means for supplying fresh air under pressure to said chamber from a remote source through said duct, and a spring pressed check valve openable under the air pressure for feeding the air to the chamber and for automatically sealing the duct when the pressure is cut off by severance of the duct at a point spaced from the sealing means.

6. A respirator comprising a breathing chamber, a pair of ducts connected with the breathing chamber, means for supplying fresh air under pressure exceeding atmospheric pressure to the chamber from a remote source through one of said ducts, means for purifying local contaminated air and supplying the same to the chamber through the other duct at atmospheric pressure, and means associated with the fresh air duct and responsive to the pressure of the air being supplied for feeding the air to the chamber and for automatically sealing the duct when the pressure is cut off by severance of the duct at a point spaced from the sealing means.

7. A respirator comprising a breathing chamber, a pair of ducts connected with the breathing chamber, means for supplying fresh air under pressure exceeding atmospheric pressure to the chamber from a remote source through one of said ducts, means for purifying local contaminated air and supplying the same to the chamber through the other duct at atmospheric pressure, and a spring pressed check valve in the fresh air duct, the valve spring being yieldabie to open the valve under the pressure of the fresh air being supplied but loaded to hold the valve closed against atmospheric pressure so that the fresh air duct is automatically sealed when the pressure is cut off by severance of the duct at a point spaced from the sealing means.

8. A respirator comprising a breathing chamber, a pair of ducts connected with the breathing chamber, means for supplying fresh air under pressure exceeding atmospheric pressure to the chamber from a remote source through one of said ducts, means responsive to pressures within the chamber for controlling the admission of said air to maintain the pressure in the chamber at a substantially constant value, means for purifying local contaminated air and supplying the same to the chamber through the other duct at atmospheric pressure, and means associated with the fresh air duct and responsive to the pressure of the air being supplied for feeding the air to the chamber and for automatically sealing the duct when the pressure is cut off.

9. A respirator comprising a breathing chamber, a pair of ducts connected with the breathing chamber, means for supplying fresh air under pressure exceeding atmospheric pressure to the chamber from a remote source through one of said ducts, means responsive to pressures within the chamber for controlling the admission of said air to maintain the pressure in the chamber at a substantially constant value, means for purifying local contaminated air and supplying the. same to the chamber through the other duct at atmospheric pressure, means responsive to pressures within the chamber for controlling the admission of said purified air to the chamber, and means associated with the fresh air duct and responsive to the pressure of the air being supplied for feeding the air to the chamber and for automatically sealing the duct when the pressure is cut off.

10. A respirator comprising a chamber, an air passage opening into the chamber, an air supply duct connected to the passage, means associated with the air passage and responsive to pressure within the chamber for automatically controlling the amount of fresh air admitted from the passage into the chamber to maintain a substantially constant pressure therein exceeding atmospheric pressure, and means for automatically closing the passage when the supply of fresh air thereto is interrupted.

11. A respirator comprising a chamber, an air passage opening into the chamber, an air supply duct connected to the passage, means associated with the air passage and responsive to pressure within the chamber for automatically controlling the amount of fresh air admitted from the passage into the chamber to maintain a substantially constant pressure therein exceeding atmospheric pressure, means for automatically closing the passage when the supply of fresh air thereto is interrupted, a second supply duct opening into the chamber, means normally closing the second duct and responsive to reduced pressure within the chamber for admitting local air through the second duct when the pressure in the chamber is below atmospheric pressure, and means for purifying the local air passing through the second duct.

12. A respirator comprising a chamber, an air passage opening into the chamber, an air supply duct connected to the passage, means associated with the air passage and responsive to pressure within the chamber for automatically controlling the amount of fresh air admitted from the passage into the chamber to maintain a substantially constant pressure therein exceeding atmospheric pressure, means for automatically closing the passage when the supply of fresh air thereto is interrupted, a second supply duct opening into the chamber, means normally closing the second duct and responsive to reduced pressure within the chamber for admitting local air through the second duct when the pressure in the chamber is below atmospheric pressure, means for purifying the local air passing through the second duct, and means in connection with the second duct for admitting compressed oxygen in quantities insufficient to actuate the fresh air control means.

13. A respirator comprising a hollow casting providing a breathing chamber and having a partition therein forming an air supply passage, an

air duct connected to the passage for supplying fresh air under pressure from a remote source, in let and outlet ports formed in the passage, an automatic pressure regulating valve mounted in connection with the outlet port, a check valve mounted in connection with the inlet port, and means in the wall of the casting adjacent the valves for regulating the valves and to give access thereto.

1%. A respirator comprising a hollow casting providing a breathing chamber and having a partition therein forming an air supply passage, an air duct connected to the passage for supplying fresh air under pressure from a remote source, inlet and outlet ports formed in the passage, an automatic pressure regulating valve mounted in connection with the outlet port, a check valve mounted in connection with the inlet port, means in the Wall of the casting adjacent the valves for regulating the valves and to give access thereto, and a second duct opening into the chamber for independently supplying air thereto.

EDWARD W. BULLARD. 

